Actually Uncle, It's more according to the weather I.E. Hot or cold. My clothing in other words. I like my old Colt. Been carrying it for a lot of years now. But in summertime with the heat, it's hard to dress appropriately where that thing doesn't "print". That ultra carries great in a holster in the small of my back so I can wear a long short sleeve shirt. I can't carry that Colt or the STX in the small of my back. I either side carry or shoulder holster them.